[C:1]([NH:6][C:7]1[CH:8]=[C:9]([OH:16])[C:10](=[CH:14][CH:15]=1)[C:11]([OH:13])=[O:12])(=[O:5])[C:2]([CH3:4])=[CH2:3].O.[C:18](OC(=O)C)(=[O:20])[CH3:19]>S(=O)(=O)(O)O>[C:18]([O:12][C:11](=[O:13])[C:10]1[C:9](=[CH:8][C:7]([NH:6][C:1](=[O:5])[C:2]([CH3:4])=[CH2:3])=[CH:15][CH:14]=1)[OH:16])(=[O:20])[CH3:19]A few drops of concentrated sulfuric acid is added to a stirring solution of 35.0 g of 4-methacrylamidosalicylic acid (prepared according to Example 1) in 350 mL of acetic anhydride at 0° C. The solution is stirred for 60 minutes at 0° C. and then for an additional 6 hours at room temperature. The reaction mixture is then poured into 800 g of cold deionized water. The solid product precipitates from solution, and is collected by filtration. The product is then air dried at room temperature to afford A-4-MASA in quantitative yield.
불러오는 중…